Refrigeration apparatus



Jan. 21, 1958 H. E. SHEETS 2,820,350

REFRIGERATION APPARATUS Filed Nov. 29, 1952 2 Sheets-Sheet l INVENTOR. HERMAN 54557-5 F/G. 4 BY 9%,... aw/2M 147' roe/vs ys Jan. 21, 1958 H. E. SHEETS 2,820,350

REFRIGERATION APPARATUS 2 Sheets-Sheet 2 Filed Nov. 29, 1952 Ame/vans INVENTOR.

HERMAN 55/155725 EM m United States Patent 2,820,350 REFRIGERATION APPARATUS Herman E. Sheets, Akron, Ohio Application November 29, 1952, Serial No. 323,207

11 Claims. (Cl. 62-115) This invention relates to refrigeration, and refrigeration apparatus, or to reversed refrigeration, such asa heat pump process of the vapor compressiontype.

The refrigeration system or apparatus of the invention is of the type that may be used in air conditioning or refrigerator units presently considered to be too small to be used with a compressor of the turbo-machinery type. The proposed unit uses a closed circuit with a refrigerant fluid therein and with a suitable compressor being included in the circuit for compressing the gas prior to its liquefaction. Previously, units below certain large sizes have used compressors predominantly of the positive displacement type as a source of compression. This type of a compressor has certain disadvantages such as the fact that it has a predetermined and built-in compression ratio, that it has low volumetric efliciency for high speeds and inlet pressures below the predetermined conditions. Also, these compressors present certain lubrication problems and they are relatively costly due to the number of parts and the accuracy required in making high speed or high compression ratio pumps. Furthermore, these types of compressors have an inherent compleXity if refrigeration at two pressures and temperature levels is required. I

The general object of the invention is to provide a new refrigeration system which includes a compression system having a variable capacity, and a variable compression ratio with minimum horsepower input over a range of condenser and evaporator temperatures.

Another important object of the invention is to use a turbo-machinery type compressor having a variable speed range to give a variable range of compression ratios in the system.

Another object of the invention to aid in obtaining the variable range of compression ratios in the system is to use an ejector pump in the refrigerator system in combination with the turbo-machinery type compressor.

Another object of the invention is to include a fluid transmission to be used in the drive means of a compressor in a refrigeration system as a controllable part of the thermo-dynamic cycle in the refrigeration system.

Another object of the invention is to provide a refrigeration system which is uncomplicated but is eflicient to operate at two pressure and temperature levels.

A further object of the invention is to provide a refrigeration system of the type described wherein for the normal operating conditions the mass flow through the refrigeration compressor is that mass flow required by the refrigerating cycle alone.

Another object of the invention comprises the provision of special control means for the supply of speed and power to the main compressor of the refrigeration means by the use of adjustable blades in the fluid' transmission driving the compressor, by density control of fluid in the transmission, or conti'olby matching the characteristics of the main compressor with corresponding characteristics of the compressor and turbine of the fluid transmission.

Another object of the invention is to use the fluid in 2,120,350 Patented Jan. 21, T1953 the fluid transmissionin the liquid state, in the vapor state, or in a mixture or combination of both states depending upon the operating conditions of the entire refrigeration system and the amount of refrigeration required.

Yet another object of the invention is to combine in a refrigeration circuit at least one compressor of the turbo-machinery type with at least one e ector pump for continuous operation, or upon intermittent demand, with a portion of the compressed refrigerant being used to operate the ejectorpump.

Another object of the invention is to place all of the rotating parts in a refrigeration system in a totally enclosed unit.

A further object of the invention is to provide a special high speed compressor wherein the driven high speed shaft is supported on the rotating shaft of the lower speed prime mover.

The foregoing and other objects and advantages of the invention will be made more apparent from the following specification.

For a better understanding of the invention, reference should be had to the accompanying drawings wherein several currently known and preferred embodiments of the invention are shown, and wherein:

Figs. 1 through 5 are diagrammatic views of refrigeration systems embodying the principles of the present invention; and

Fig. 6 is a fragmentary elevation, partially shown in section, of a fluid transmission and compressor embody ing the principles of the invention.

in the drawings and the specification, corresponding numerals will be used to refer to corresponding parts.

The refrigeration apparatus is connected in a closed cycle and includes a turbo-machinery type compressor usually driven by a fluid transmission, a condenser, a receiver, and an evaporator. As hereinafter described, special members, such as a jet pump, extra heat exchangers, a special fluid transmission, etc. may be provided and be connected in the system as hereinafter described in detail.

In the refrigeration system of the invention, a single fluid may be used as the refrigerant and in the fluid transmission and I have found that ordinary methods of heat removal from the transmission, such as continuous or cycling addition to and/or discharge of fluid from the fluid transmission results in inefficient operation of the refrigeration cycle and requires an unnecessarily large amount of power from the prime mover.

The actual heat removal from the system in the refriger ation cycle takes place in the condenser. I have found that in a refrigerating system being operated with F-IZ as refrigerant between 40 evaporator temperature and condenser temperature and if the temperature in the fluid transmission is kept close to the temperature of the condenser and if the temperature increase within the fluid transmission is kept to a limit of 10 F., then with the usual efliciency in the fluid transmission the primary compressor has to supply 40% more mass flow and also 40% more power to accomplish the heat removal. In addition to the increased power of 40%, the power requirements for the prime mover are increased beyond this value by the efficiency of the fluid transmission. A 10 temperature differential may be considered small to aflect the density for fluids such as air. However, with typical refrigerants or with F-1Z as fluid the change in density of its vapor is considerable for a change of temperature on the order of 10. F.

The main compressor in the refrigeration system is operated at constant or variable speed depending upon operating conditions and the pressure differential between condenser and evaporator. Thus the speed of the comressor is controlled by suitable regulating means in the fluid transmission. Such regulating means consist of the heat exchanging means of the fluid transmission with at least one additional type of control which may be: variable vanes in the fluid transmission, density control by regulation of the pressure, heat and/or moisture of the vapor in the fluid transmission, or by matching the characteristics of the main compressor with corresponding characteristics of the compressor and turbine in the fluid transmission.

One representative embodiment is shown diagrammatically in Fig. l and this illustrates the thermodynamic cycle of the single fluid, compression refrigeration process of the invention. A single fluid, such as Freon 12 or other known refrigerants, is used in the refrigeration apparatus generally referred to by the numeral 1 and which includes a turbo-machinery type compressor 2, the outlet of which is connected to a suitable heat exchanger 3 that is used to cool the gases delivered by the compressor 2. These cool gases flow from the heat exchanger 3 to a second and usually larger heat exchanger, or condenser 4 wherein the gases are condensed and flow to a receiver 5 for collection therein. The refrigerant passes from the receiver 5 to an evaporator 6 through a suitable controllable expansion valve or other expansion device 7. The term expansion valve in the specification and claims is taken to mean any conventional expansion device. Thus the refrigerant fluid in the evaporator 6 is released therein at a pressure p while gas leaving the evaporator s flows through a second valve 8 that can be used to control the return flow of the refrigerant in the refrigeration cycle. Such exhaust gas from the evaporator 6 is drawn into and through a conventional jet, or ejector pump 9 for compression therein. The drive inlet of the ejector pump 9 is connected through a conduit 10 and control valve 11 to the outlet side of the heat exchanger 3 so that a small portion of the gases passing from the compressor 2 may flow directly to the ejector pump 9 to provide the drive fluid therefor. The valve 11 is used to control the inlet pressure and gas supply for the ejector pump 9 for flow of fluid thereto and therethrough. The outlet pressure of the ejector pump 9 is higher than the low pressure of fluid passing through the evaporator 6. Gases leaving the ejector pump 9 pass through a conduit 200 to the inlet for the compressor 2. Such gases flowing to the compressor 2 enter at an intermediate pressure p to which they have been raised by the ejector pump from the pressure p at which the gases flow from the evaporator 6. By adjusting the valve 7, the pressure p can be regulated within wide limits. The compressed gas leaving the compressor 2 is at an elevated pressure 2 The vapor flowing to the ejector pump 9 may be precooled if high efliciency is important. The ejector pump has no moving parts and is of conventional construction. By regulating the ratio of the mass flow as well as pressure of the driving fluid to those of the suction fluid, a wide range of capacities and pressures is maintained so that this pump can maintain an optimum compression ratio over a wide range of condenser and evaporator pressures. Usually the ejector pump 9 is operated on a reasonably small compression ratio in order to achieve good efficiency since the difluser of the pump can be limited to subsonic flow of vapor therethrough. By arranging the ejector pump in series with the compressor, the compressor will operate at a higher rate of mass flow and a lower compression ratio than would otherwise be possible.

A slightly more complex thermodynamic cycle is shown in Fig. 2 of the drawings wherein the same general type of a system is provided as is shown in Fig. 1, and wherein the parts are indicated by corresponding numerals to those used for the apparatus shown in Fig. l, with the suflix a being added thereto. Thus a multi-stage compressor 2 a receiver 5 and an evaporator 6* are shown. Additionally, evaporators l3 and 14 are provided in the system with the evaporator 13 being connected through an expansion valve 15 to the reveiver 5 The outlet of the evaporator 13 connects to a conduit 16 that communicates with conduit 200 that connects the discharge end of the ejector pump 9 to the inlet of the compressor 2* so that the discharge pressure for the evaporator 13 would be the pressure p the outlet pressure for the ejector pump 9. The evaporator 14- is connected through an expansion valve 17 to the receiver 5 and the outlet for such evaporator 14 is connected to the compressor 2 at the second, or subsequent stage inlet thereof, usually at a pressure above that of the inlet pressure of the compressor. Hence :all three evaporators 6 13 and 14 can operate at different pressures and thus have three temperature levels set up in the apparatus of the invention with no more moving parts than in the apparatus of Fig. 1.

Yet a further embodiment of the invention where the novel refrigration cycle of the invention includes the use of a fluid transmission for connecting the prime mover to the compressor, is shown in Fig. 3. The fluid transmission provided is an important element of the invention as it permits the use of high speed centrifugal compressors of small capacity in the refrigeration apparatus, since the fluid transmission normally functions as a speed increaser in the invention. I prefer to use the same fluid as a reactant in the fluid transmission as is used in the compressor of the refrigeration system. In larger size units, the fluid may be a liquid in the transmission while it probably would be used as a vapor in the smaller size transmissions. The compressor may either charge or unload the fluid transmission with relation to the fluid received therein and thus eliminate the use of a separate pump for such purpose. Fluid transmissions as designed today permit speed change ratios in the order of 15 to l in a single stage resulting in a maximum speed increase to 52,000 R. P. M., or a speed decrease to about 230 R. P. M. from a 3500 R .P. M. prime mover speed. This speed change ratio is not constant but can be varied as desired. thus permitting operation of the compressor over a wide range of speeds so that variable compression ratios and capacities over a predetermined range can be accomplished. When 'a vapor fluid transmission is used, even a wider range of flexibility of operation is possible by varying the density of the vapor in the fluid transmission. A preferred solution for such an arrangement may con sist in operating the vapor density in the fluid transmis sion automatically at a fixed relationship to the pressure in the condenser and/or evaporator of the system. Therefore, for high condenser temperatures and pressures the fluid transmission will operate with a higher density vapor and automatically transmit more horsepower to the compressor than would be required for low condenser temperatures. Due to the variable speed and horsepower provided by the fluid transmission, the entire compression system can be operated at optimum efliciency over a wide range of operating conditions.

This refrigeration apparatus of Fig. 3 is illustrated as including a suitable constant speed prime mover, such as an electric motor 20, which is connected through a fluid transmission indicated as a Whole by the numeral 21 to the compressor 22 for driving it. Usually the motor 20, fluid transmission 21 and compressor 22 are mounted in a sealed, or enclosed unit 23 to eliminate leaks of refn'g erant vapor and to aid in reducing the noise produced. The compressed refrigerant gas from the compressor 22 passes to a suitable heat exchanger and condenser 24. Liquid from the condenser 24 collects in a receiver 25 and it flows from the receiver 25 through a conduit 26 in which a controllable expansion device 27 is provided for regulating flow of the refrigerant liquid into an evaporator 28. The exhaust gas from the evaporator 28 passes through a conduit 29 to the unit provided for driving the compressor 22.

As an important feature of the invention, the unit 23 preferably includes a suitable heat exchanger 30 which usually is associated with the motor 20 to withdraw heat therefrom during operation of the refriger a tionapparatus and to maintain such motor at a desirable temperature level. Next the refrigerant as preferably flows through another heat exchanger 31 and this heat exchanger 31 normally is associated with the fluid transmission 21 for withdrawing heat therefrom. The capacities of the heat exchangers 30 and 31 are calculated with relation to the amounts of heat to be withdrawn from the member'associated therewith to retain such member within desired temperature limits. The refrigerant gas completes its cycle by passing to the inlet of the compressor 22.

As another important feature of this embodiment of the invention, the outlet of the compressor 22 connects to the fluid transmission 21 by a conduit 32' in which a suitable control valve 33 is positioned. Thus, by opening the valve 33, any desired pressure up to the outlet pressure of the compressor 22 can be set up within the transmission 21. .The fluid transmission in thisjinstapce has vapor therein due to the receipt of gasfrom the cornpressor 22. When it is desired to reduce the density of the fluid in the fluid transmission and to reduce the pressure at which such transmission operates, then a valv e 3 4 may be opened which is present in a conduit 35 connect ing the fluid transmission 21 to the heat exchanger. 31, usually intermediate the extremities thereof. It will thus be seen that the heat exchangers provided constantly and automatically maintain the fluid transmission and motor at desired temperature levels as a part of. the closed'circuit thermodynamic refrigeration cycle of the invention. In some instances, it may be desirable to omit the conduit 35 and valve 34 so that no refrigerant flow through the fluid transmission 21 may be had. I v

In the embodiment of the invention shown in Fig. 3, the hydraulic transformer operates at temperatures in the vicinity of the condenser temperature and there is a considerable amount of super heat available in the vapor leaving the evaporator for cooling purposes. Theheat available, in the vayor is usually in excess of what is required for cooling means'for the hydraulic transmission, if the efficiency of the hydraulic transmission is above. 80%. Thus the same mass flow would be handled by'the main compressor as would be requiredwithout the additional cooling caused by the hydraulic transmission. The inlet temperature of the vapor fed to the. compressoris slightly higher so that the inlet volume is increased due to the temperature increase in the heat exchangers, anda slightly larger amount of enthalpy is required forcompression work. p j v t It will be seen that the fluid transmission '21 functions as an accumulator in that varied amounts of refrigerant fluid can be stored therein for changing the operating conditions in the refrigeration circuit and/orthe fluid transmission.

Yet another embodiment of the invention is shown in Fig. 4 wherein the liquid refrigerant is used as the fluid in the fluid transmission. in this instance, a compressor unit 39 is shown that includesa turbo-machinery type compressor 40, a fluid transmission 41 and a drive motor 42, as in the embodiment of the invention shown in Fig.3. The compressor output connects through a condenser 43 to a receiver 44 which in turn is connected through an expansion device 45 to an evaporator 46. The fluid trans' mission 41 receives refrigerant liquid from the receiver 44 through a conduit 47 which preferably has a control valve 48 therein to regulate flow of liquid to the transmission 41, and provide additional liquid in the transmission at desired times. Usually the liquid flowing to the fluid transmission-41 should be specially cooled before flow to the transmission and thus a heatexchanger 49 is provided and the cooling circuit thereof receives refrigerant fluid from the outlet of the' evaporator 46;" The other. circuit of theheat' exchanger 49 has a member 50 honnected-in conduit '47 so that the' liquid inlco'nduit 47...-p'asses through the heat'exchanger for the desired cooling action on the fluid in such conduit. When-ibis desired to exhaust liquid from the fluid transmission 41, a control valve 51 in a conduit 52 leading from the fluid transmission is opened. This conduit connects to the input side of the evaporator 46.

In the embodiment of the invention of Pig. 4, it is assumed that the temperature of the liquid in the hydraulic transmission 41 is great enough so as to bring the temperature of the refrigerant to a value above the usual condenser temperature. Then the cycle of refrigeration is improved by use of an additional heat exchanger 53 which is provided intermediate the inlet of the compressor 49 and the outlet of a fluid transmission heat exchanger 54 for cooling the gas to about condensing temperature. A heat exchanger 55 is also present in the compressor unit 39 and usually is used to cool the motor 42. Of course, the outlet of the heat exchanger 53 connects to the compressor inlet. The embodiment of the invention shown in Fig. 4 is particularly advantageous if there is a large temperature diflerential between the evaporator 46 and the condenser 43 since a large amount of power per ton of refrigeration is required and a correspondingly large volume of heat is removed from the fluid transmission as a large amount of power is being transmitted therethrough. For smaller power requirements with consequent less heat generation in the fluid transmission, the fluid transmission 41 may be cooled by the use of only one heat exchanger 54. Or, possibly the temperature of the fluid transmission may be controlled solely by passage of refrigerant therethrough by control of the valves 48 and 41. Refrigerant liquid may flow continuously through the fluid transmission 41 if valves 48 and 51 are open continuously. Such action still does not set up any excessive load on the compressor 40 or reduce its efiiciency greatly from a refrigeration viewpoint as such liquid from the fluid transmission flows through the evaporator 46 for cooling action therein.

in some instances, it is desirable to combine a turbocompressor with one or more ejector pumps in a refrigeration system, as such a system permits the operation of the compressor with a larger flow capacity and a smaller compression ratio than would otherwise be possible. This results in higher efficiency of the rotating compressor. Accordingly, the embodiment of the invention shown in Fig. 5 has been provided and it also permits a riahle density control to be provided in the fluid transmi The refrigeration circuit shown in Fig. 5 is quite similar to the circuit shown in Fig. 2 but several modifications have been made thereto. The basic circuit includes a drive motor 60, a fluid transmission 61 and a turbotype multi-stage compressor 62. The compressor 62 connects through a heat exchanger 63 and a condenser 64 to a receiver 65. This receiver connects to evaporators 66, 67 and 68 that have suitable expansion valves associated therewith to control flow of fluid therethrough and with the outlets of the evaporators connecting, respectively, to the suction inlet of an ejector pump 69, the outlet of the ejector pump 69 which is a conduit 7 0, and to the second stage inlet of the compressor 62. The drive gas for the ejector pump 69 is received through a conduit 71 which hasa control valve 72 therein and connects to the high pressure side of the compressor 62 usually immediately before the condenser 64. The fluid transmission of. may receive refrigerant liquid from the receiver 65 through a conduit 73, which has a control valve 74 therein, and vapor from the fluid transmission 61 will be exhausted therefrom through a conduit 75 which connects to the suction inlet of the ejector pump 69. A control valve 76 is provided for regulating the desired intermittent flow of gas from the fluid transmission 61. Hence refrigerant only flows through the fluid transmission intermittently as permitted by opening of the valves 74 and 76. Liquid is permitted to flowto the transmission 61 for liquid injectionttherein when. a liquid-vapor mixture or wet vapor is. used in at; least part of the fluid transmission, and it increases t'he densityrangeto wider-limits for in transmission. The fluid transmission is connected to receive high pressure refrigerant gas from the outlet of the compressor 62, when desired, by a conduit 77 that has a control valve 78 therein. Thus a density control is provided for varying the pressure in the fluid transmission and making the maximum pressure therein equal to the outlet pressure of the compressor 62 whereas the mini mum pressure may be made equal to the suction pressure of the ejector pump 69.

The use of ejector pumps in the embodiment of the invention shown in Fig. 5 may be continuous or intermittent. If an extremely wide range of pressures between condenser and evaporator is only occasionally quired, the ejector cycle is particularly advantageous as it permits the extension of range at low The jet pump 69 may be used only for density regulation in fluid transmission 61 if the evaporator 66 is omitted from the refrigeration circuit.

Fig. 5 also shows the use of a separate heat exchanger 79 for the hydraulic transmission. This heat exchanger 7 9 may discharge into the heat exchanger 63 provided the fluid transmission 61 operates at a maximum density and an absolute pressure near the condenser pressure. The required pressure drop through such heat exchanger '79 is produced by the compressor in the hydraulic transformer.

Fluid admission to the fluid transmission is controlled through the valve V a function of the temperature increase of the fluid in the fluid transmission and resultant pressure increase therein. As soon as a predetermined temperature increase is reached in the fluid transmission, the fluid adde through valve 78 results in a sumciently high pressure in the heat exchanger '7) to overcome the pressure resistance of a check valve 362, which is connected between the exchanger i9 and the heat exchanger 63 and gas flows into heat exchanger 63 and through the remainder of the refrigeration circuit to produce a refrigeration action before again reaching the compressor. The system a continuous or cyclic flow from the primary comp essor to the hydraulic transformer as well as a continuous or cyclic discharge from the fluid transmission to the heat exchanger '79. in this system, the total flow of refrigerant through the main compressor 62 is unchanged as the fluid from the fluid transmission is subsequently used in the evaporator portion of the system to produce cooling action.

Where variable density regulation in the fluid transmission is used, and the density and pressure in the fluid transmission 61 fall below a certain value, flow discharge into the heat exchanger 63 is not possible. Thus, a return line from the heat exchanger to the fluid transmission 61 is provided by conduit 31 and flow of fluid is controlled by a pressure and temperature operated valve 82 provided in such conduit and opening when a predetermined den sity exists in the fluid transmission. The fluid transmission in such instance is cooled by the heat exchanger 79 and the compressor in the fluid transmission provides the pressure differential for fluid flow through the heat exchanger.

Fig. 6 shows by way of example a fragmentary section of a single stage centrifugal compressor and associated drive means wherein an entire drive unit and compressor is provided and is positioned in a housing A constant speed electric motor 102 is provided as the prime mover and its drive shaft 103 protrudes from the motor. In small high speed compressors, it is especially important that the driven shaft has a high critical speed and low circumferential speed in the bearing. A special embodiment of the invention is shown in Fig. 6 provided for the driven shaft of a centrifugal compressor 104- to be carried by the motor drive shaft 103 thus having the structural advantages described above.

A housing 105 is provided for the fluid transmission 106. The fluid transmission includes a pump impeller 107, which converts the mechanical energy of the prime mover shaft into potential of pressure energy of the fluid in the transmission,-a stator 108, which adjusts the direction of flow and while not changing the total pressure of the fluid divides into the predetermined division between static and dynamic pressures of the fluid, and a turbine rotor to which the fluid enters from the stator with a predetermined direction of flow, and static and dynamic pressures. The turbine rotor 110 converts the fluid energy into mechanical energy of speed and torque of the desired values, thus permitting a speed increase or decrease of the secondary shaft, as desired.

The pump impeller, stator and turbine rotor may be of multistage or single stage and of axial or centrifugal design, but only the single stage design is shown in Fig. 6.

The prime mover shaft 103 drives the pump impeller 107 which is carried thereby and which is shown as a radial type impeller. This impeller discharges fluid into a radially outer portion 109 of a toroidal space between the impeller 107 and the stator 108 and from which the fluid is admitted to the stator 108. The fluid leaves the stator 108 and flows through a radially inner portion 139 of the toroidal space into the turbine rotor 110, this rotor being shown as an axial type. The turbine rotor 110 is supported on a sleeve 111 journaled on the shaft 103 by suitable bearings 112. Thus the output of the transmission 166 is available in the sleeve 111. An impeller 113 for the compressor 104 is secured to and driven by the sleeve 111 while a housing 114 for the compressor is provided and is shown as carried by the housing 105.

As a feature of this embodiment of the invention, the refrigerant gas is suitably discharged from the evaporator of the refrigeration system, such as the evaporator 28 of the apparatus shown in Fig. 3, into a prime mover housing 121 which connects to the housing 101. Such gas flows around and through the prime mover 102 for the purpose of cooling the prime mover and then enters the housing 101 through holes 122. The gas cools the fluid transmission 106 by flowing over and around the transmission housing 105 to a compressor inlet 115 in the housing 114. Compressed refrigerant gas flows from the compressor 104 through a conduit 116 to a condenser (not shown) in refrigeration apparatus. A control valve 117 is provided in a conduit 118 that connects conduit 116 to the fluid transmission 106 for flow of compressed fluid thereto. Refrigerant gas may be returned to the remainder of the refrigeration apparatus from the fluid transmission through any conventional means such as a conduit 119 with a control valve 120 therein.

If apparatus as in Fig. 5 is used with flow of refrigerant directly to the compressor 104, an input conduit 131 extends to a point adjacent the suction inlet 115 of the cornpressor 104 shown in Fig. 6, which conduit 131 connects to the refrigeration circuit (not shown) with which the drive and compressor unit 100 is used.

It will be understood that the expression flow control means may be used to indicate the use of a conduit with a valve therein, or similar conventional apparatus for controlling the flow of refrigerant from one portion of the apparatus to another. Valves are included in the term expansion device as used in the specification and claims, and such valves are conventionally shown in the drawings. The heat exchangers shown diagrammatically in Figs. 1 to 5 may be of the type disclosed in Fig. 6, or else they may be other means such as cooling coils, etc.

In apparatus as in Fig. 3, the condenser 24 operates usually at the temperature of the surrounding medium and such temperature may vary. The surrounding medium may, for example, be air or water. High temperature in the condenser produces high pressure in the condenser and this produces a high pressure in the fluid transmission 21. The pressure changes in the fluid transmission vary the density of the transmission fluid and high density fluid provides greater power transmission than low density fluid in the fluid transmission. This automatically lightens the load on the prime mover at low condenser temperatures.

Variable fluid transmissions of the type which may be used in practice of the present invention are shown and described in articles entitled Studebakers Automatic Transmission, page 20, S. A. E. Journal, March 1950, and Chevrolets Automatic Transmission, page 27, S. A. B. Journal, March 1950. These transmissions may have stators which may be either fixed or rotated to vary the action thereof.- Or, the turbine blades may be pivotally positioned and be moved by one control ring connected thereto to vary the angular setting thereof.

What is claimed is:

1. A closed circuit fluid refrigeration apparatus comprising a turbo-machinery ty-pe compressor including a fluid transmission; circuit means including a condenser connected to the outlet of said compressor; a receiver connected to said condenser for receiving and storing refrigerant liquid; an evaporator, and an expansion device connecting said receiver to said evaporator for expansion of refrigerant therein; said fluid transmission having reffigerant fluid therein; means connecting the outlet of said evaporator to the inlet of said compressor for refrigerant flow therebetween; and flow control means normally closed at static load conditions operatively connecting said fluid transmission in parallel with part of said circuit means but with all refrigerant fluid passing through said compressor, said flow control means being independently operable to control flow of refrigerant fluid both to and from said fluid transmission to control the fluid density therein.

2. A closed circuit fluid refrigeration apparatus comprising a turbo-machinery type compressor including a fluid transmission; circuit means including a condenser connected to the outlet of said compressor; a receiver connected to said condenser for receiving and storing refrigerant liquid; an evaporator, and an expansion device connecting said receiver to said evaporator for expansion of refrigerant therein; flow control means connecting the outlet of said compressor to said fluid transmission for passage of refrigerant fluid thereto, said fluid transmission having refrigerant fluid therein; means connecting the outlet of said evaporator to the inlet of said compressor for refrigerant flow therebetween; and intermittently operable flow control means operatively connecting an outlet of said fluid transmission to said last named connecting means; said flow control means permitting control of the density of refrigerant fluid in said fluid transmission.

3. A closed circuit fluid refrigeration apparatus comprising a compressor unit including a turbo-machinery type compressor connected in the path of flow of fluid in the apparatus, drive means, and a turbo-machinery type fluid transmission connecting said drive means to said compressor; a condenser connected to the outlet of said compressor to receive gas therefrom for condensation; an evaporator means including an expansion device connecting said condenser to said evaporator for expansion of refrigerant fluid therein; controllable but normally closed means at all load conditions connecting the outlet of said compressor to said fluid transmission for passage of refrigerant fluid thereto; said fluid transmission having refrigerant fluid therein and being connected in a controlled circuit in parallel with said evaporator outlet and condenser inlet; a heat transfer member for cooling said fluid transmission; and means connecting said heat transfer member in series intermediate the outlet of said evaporator and the inlet of said compressor.

4. A closed circuit fluid refrigeration apparatus comprising a compressor unit including a turbo-machinery type compressor connected in the path of flow of fluid in the apparatus, a drive motor, and a turbo-machinery type fluid transmission connecting said drive motor to said compressor; a condenser connected to the outlet of said compressor; a receiver connected to said condenser to receive liquid therefrom; an evaporator; an expansion device connecting said receiver to said evaporator for expansion of refrigerant therein; means connecting the outlet of said compressor to said fluid transmission for passage of refrigerant fluid thereto, said fluid transmission having a refrigerant fluid therein; heat transfer means for cooling said drive motor; heat transfer means for cooling said fluid transmission; means connecting said heat transfer means in series intermediate the outlet of said evaporator and the inlet of said compressor to control the operational temperatures of said drive motor and fluid transmission; and regulatable outlet flow control means connecting said fluid transmission to the inlet circuit of said compressor to aid in controlling the operating fluid density in said fluid transmission.

5. A closed circuit fluid refrigeration apparatus, a refrigeration circuit having a return conduit and an evaporator therein, a compressor unit including a turbo-machinery type compressor having an inlet, a fluid transmission, drive means for said fluid transmission, means enclosing said compressor, fluid transmission and drive means; and means feeding refrigerant fluid from said return conduit to said enclosing means for cooling of said drive means and fluid transmission, the inlet of said compressor receiving refrigerant vapor after cooling flow past said fluid transmission, said fluid transmission having refrigerant fluid therein, said refrigerant fluid passing into and circulating through said fluid transmission for transmission action therein, the same refrigerant fluid in a gaseous state being discharged from said evaporator at the out let thereof and being used in said compressor, and in said enclosure means for cooling the fluid transmission and said drive means.

6. A closed circuit fluid refrigeration apparatus comprising a turbo-machinery type compressor; circuit means including a condenser connected to the outlet of said compressor; a receiver connected to said condenser; an evaporator, and an expansion device connecting said receiver to said evaporator; means connecting the outlet of said evaporator to the inlet of said compressor; a fluid transmission means for said compressor; and regulat-able means normally closed for static operating conditions operatively connected to the outlet of said compressor and connecting to said fluid transmission means, said fluid transmission means having a predetermined amount of a refrigerant fluid in an evaporated state therein and acting as an accumulator, said fluid transmission means being adapted to have more fluid mass therein when the refrigerant operates under relatively large pressure and temperature differentials between said condenser and said evaporator and requires relatively large forces to drive said compressor.

7. A closed circuit fluid refrigeration apparatus comprising a compressor unit including a turbo-machinery type compressor connected in the path of flow of fluid in the apparatus, drive means, and a turbo-machinery type fluid transmission connecting said drive means to said compressor; a condenser connected to the outlet of said compressor to receive gas therefrom for condensation; an evaporator; means including an expansion device connecting said condenser to said evaporator for expansion of refrigerant therein; means connecting the outlet of said compressor to said fluid transmission for passage of refrigerant fluid thereto; said fluid transmission having refrigerant fluid therein; a heat transfer member for cooling said fluid transmission; and means connecting said heat transfer member in series intermediate the outlet of said evaporator and the inlet of said compressor.

8 A closed circuit fluid refrigeration apparatus comprising a compressor unit including a turbo-machinery type compressor connected in the path of flow of fluid in the apparatus, a drive motor, and a turbo-machinery type fluid transmission connecting said drive motor to said compressor; a condenser connected to the outlet of said compressor; a receiver connected to said condenser; an evaporator; an expansion device connecting said receiver to said evaporator for expansion of refrigerant therein;

means connecting the outlet of said compressor to said fluid transmission for passage of refrigerant fluid thereto, said fluid transmission having refrigerant fluid therein; a heat transfer means for cooling said drive motor, heat transfer means for cooling said fluid transmission; and means connecting said heat transfer means in series intermediate the outlet of said evaporator and the inlet of said compressor to control the operational temperatures of said drive motor and fluid transmission.

9. A closed circuit fluid refrigeration apparatus comprisiing a turbo-machinery type compressor; circuit means including a condenser connected to the outlet of said compressor; a receiver connected to said condenser; an evaporator, and an expansion device connecting said receiver to said evaporator; means connecting the outlet of said evaporator to the inlet of said comp cssor; an accumulator means; regulatable means normaliy closed for static operating conditions operatively connected to the outlet of said compressor and connecting to said accumulator, and regulatable means normally closed for all static operating conditions operatively connecting said accumulator to said circuit means adjacent the inlet of said compressor.

10. A closed circuit fluid refrigeration apparatus comprising a turbo-machinery type compressor including a fluid transmission; circuit means including a condenser connected to the outlet of said compressor; a receiver connected to said condenser for receiving and storing refrigerant liquid; an evaporator, and an expansion device connecting said receiver to said evaporator for expansion of refrigerant therein; said fluid transmission having refrigerant fluid therein; means connecting the outlet of said evaporator to the inlet of said compressor for refrigerant flow therebetween; flow control means normally closed at static load conditions operatively connecting said fluid transmission to the outlet of said compressor, and flow control means normally closed at static load condi tions connecting said fluid transmission to the inlet circuit of said compressor.

11. In a closed circuit refrigeration apparatus, a primary compressor unit including a turbo-machinery type compressor including a stationary casing and an impeller, a fluid transmission including a turbine rotor and a transmission impeller, drive means for said fluid transmission and including a drive shaft extending into said fluid transmission and connected to and driving said transmission impeller, a sleeve supporting said turbine rotor and connecting to the impeller of said primary compressor, hearing means iournalling said sleeve on said drive shaft, a refrigeration circuit having an evaporator therein; means enclosing said compressor, fluid transmission and drive means; and means for feeding refrigerant fluid from said evaporator to said enclosing means for cooling of said drive means and fluid transmission, said fluid transmission having refrigerant fluid therein, said refrigerant fluid passing into and circulating through said fluid transmission for transmission action therein, the same refrigerant fluid in a gaseous state being discharged from said evaporator at the outlet thereof being usable in said compressor and in said enclosure means for cooling the fluid transmission and the drive means.

References Cited in the file of this patent UNITED STATES PATENTS 1,790,237 King Jan. 27, 1931 1,840,876 Rayburn Jan. 12, 1932 1,858,517 Marshall May 17, 1932 1,871,244 Stewart Aug. 9, 1932 2,109,997 Hoffman Mar. 1, 1938 2,273,213 McCloy Feb. 17, 1942 2,249,882 Buchanan July 22, 1944 2,411,347 Trumpler Nov. 19, 1946 2,530,293 De Lancey Nov. 14, 1950 FOREIGN PATENTS 361,389 Great Britain Nov. 16, 1931 

